Recording signal amplifier apparatus

Abstract

A recording amplifier apparatus comprises first and second differential amplification means connected to each other with wires. The second differential amplification means is disposed close to a rotary drum by extending the wires. It is thus possible to restrain generation of a distributed capacity by the wires to a minimum.

What is claimed is: 
     
       1. A recording signal amplifier apparatus wherein a recording signal is amplified and supplied to a rotary head mounted on a rotary drum wound with a magnetic tape, comprising: first differential amplification means consisting of first and second transistors which have bases to which said recording signal to be amplified is inputted, emitters supplied with constant currents, and collectors from which amplification outputs related to said recording signal are obtained; and   second differential amplification means consisting of third and fourth transistors which have emitters connected to said collectors of said first and second transistors for receiving said amplification outputs related to said recording signal, and bases provided with a constant potential, collector outputs of said third and fourth transistors relating to said recording signal being supplied to said rotary head;   said second differential amplification means being disposed in close proximity to said rotary drum by extending wires between said collectors of said first and second transistors and said emitters of said third and fourth transistors, and said first differential amplification means being disposed at a location more remote from said rotary drum than said second differential amplification means, whereby an effect of capacitance of said wires is reduced, wherein said second differential amplification means is provided on another circuit substrate separate from a substrate for said first differential amplification means, which is connected with said second differential amplification means via an exclusive cable including said wires.   
     
     
       2. The recording signal amplifier apparatus according to claim 1, wherein a third differential amplification means which consists of said fifth and sixth transistors is provided as a front stage of said first differential amplification means, wherein bases of said fifth and sixth transistors are supplied with said record signals, and collectors of said fifth and sixth transistors are connected to said bases of said first and second transistors. 
     
     
       3. The recording signal amplifier apparatus according to claim 1, wherein said recording signal is a digitized data signal. 
     
     
       4. A recording signal amplifier apparatus wherein a recording signal is amplified and supplied to a rotary head mounted on a rotary drum wound with a magnetic tape, comprising: first differential amplification means consisting of first and second transistors which have bases to which said recording signal to be amplified is inputted, emitters supplied with constant currents, and collectors from which amplification outputs related to said recording signal are obtained; and   second differential amplification means consisting of third and fourth transistors which have emitters connected to said collectors of said first and second transistors for receiving said amplification outputs related to said recording signal, and bases provided with a constant potential, collector outputs of said third and fourth transistors relating to said recording signal being supplied to said rotary head;   said second differential amplification means being disposed in close proximity to said rotary drum by extending wires between said collectors of said first and second transistors and said emitters of said third and fourth transistors, and said first differential amplification means being disposed at a location more remote from said rotary drum than said second differential amplification means, whereby an effect of capacitance of said wires is reduced, wherein said second differential amplification means includes an output transformer, a midpoint of a primary winding of which is connected to a power source, wherein both ends of said primary winding of said output transformer are respectively connected to collectors of said third and fourth transistors, a secondary winding of said output transformer is connected to a fixed-side winding of a rotary transformer rotating with said rotary head, and said collector outputs of said second differential amplification means are applied to said rotary head through said output transformer and said rotary transformer.   
     
     
       5. A recording signal amplifier apparatus, comprising: a source of input signals to be recorded by a rotary head mounted on a rotary drum wound with a magnetic tape;   a first differential amplifier means having a first and a second transistor each having a base to which signals representative of said input signals are inputted, an emitter supplied with a constant current signal, and a collector from which an output signal representative of an amplified output of said signals representative of said input signals are obtained, said first differential amplifier means being located at a location relatively remote from said rotary drum;   a second differential amplifier means having a third and a fourth transistor each having an emitter respectively connected to a collector of said first and said second transistors in said first differential amplifier means by wires for receiving said output signal representative of an amplified output of said signals representative of said input signals, a base provided with a constant potential, and a collector from which outputs of said third and fourth transistors representative of said input signals are provided to said rotary head, said second differential amplifier means being located at a location nearer to said rotary drum than said first differential amplifier means, said wires being extended between said emitters of said third and fourth transistors to said collectors of said first and second transistors, whereby an effect of distributed capacitance of said wires is reduced, wherein said second differential amplification means is provided on another circuit substrate separated from a substrate for said first differential amplification means, which is connected with said second differential amplification means via an exclusive cable including said wires.   
     
     
       6. The recording signal amplifier apparatus according to claim 5, wherein third differential amplification means which consists of said fifth and sixth transistors is provided as a front stage of said first differential amplification means, wherein bases of said fifth and sixth transistors are supplied with said record signals, and collectors of said fifth and sixth transistors are connected to said bases of said first and second transistors. 
     
     
       7. The recording signal amplifier apparatus according to claim 5, wherein said recording signal is a digitized data signal. 
     
     
       8. A recording signal amplifier apparatus, comprising: a source of input signals to be recorded by a rotary head mounted on a rotary drum wound with a magnetic tape;   first differential amplifier means having a first and a second transistor each having a base to which signals representative of said input signals are inputted, an emitter supplied with a constant current signal, and a collector from which an output signal representative of an amplified output of said signals representative of said input signals are obtained, said first differential amplifier means being located at a location relatively remote from said rotary drum;   a second differential amplifier means having a third and a fourth transistor each having an emitter respectively connected to a collector of said first and said second transistors in said first differential amplifier means by wires for receiving said output signal representative of an amplified output of said signals representative of said input signals, a base provided with a constant potential, and a collector from which outputs of said third and fourth transistors representative of said input signals are provided to said rotary head, said second differential amplifier means being located at a location nearer to said rotary drum than said first differential amplifier means, said wires being extended between said emitters of said third and fourth transistors to said collectors of said first and second transistors, whereby an effect of distributed capacitance of said wires is reduced, wherein said second differential amplification means includes an output transformer, a midpoint of a primary winding of which is connected to a power source, wherein both ends of said primary winding of said output transformer are respectively connected to collectors of said third and fourth transistors, a secondary winding of said output transformer is connected to a fixed-side winding of a rotary transformer rotating with said rotary head, and said collector outputs of said second differential amplification means are applied to said rotary head through said output transformer and said rotary transformer.   
     
     
       9. A recording signal amplifier apparatus, comprising: a rotary drum about which a magnetic tape is wound;   a rotary head mounted on said rotary drum said and having a rotary transformer with a movable coil and a fixed coil;   a transformer having its secondary connected to said fixed coil of said rotary transformer;   a source of input signals to be recorded by a rotary head mounted on a rotary drum wound with a magnetic tape;   a first differential amplifier means having a first and a second transistor each having a base to which signals representative of said input signals are inputted, an emitter supplied with constant current signal, and a collector from which an output signal representative of an amplified output of said signals representative of said input signals are obtained, said first differential amplifier means being located at a location relatively remote from said rotary drum;   a second differential amplifier means having a third and a fourth transistor each having an emitter respectively connected to a collector of said first and said second transistors in said first differential amplifier means by wires, a base provided with a constant potential, and a collector from which outputs of said third and fourth transistors are provided to said rotary head, said second differential amplifier means being located at location nearer to said rotary drum than said first differential amplifier means, said wires being extended between said emitters of said third and fourth transistors to said collectors of said first and second transistors, whereby a effect of distributed capacitance of said wires is reduced, wherein said second differential amplification means is provided on another circuit substrate separated from a substrate for said first differential amplification means, which is connected with said second differential amplification means via an exclusive cable including said wires.   
     
     
       10. The recording signal amplifier apparatus according to claim 9, wherein a third differential amplification means which consists of said firth and sixth transistors is provided as a front stage of said first differential amplification means, wherein bases of said fifth and sixth transistors are supplied with said record signals, and collectors of said fifth and sixth transistors are connected to bases of said first and second transistors. 
     
     
       11. The recording signal amplifier apparatus according to claim 9, wherein said recording signal is a digitized data signal. 
     
     
       12. A recording signal amplifier apparatus, comprising: a rotary drum about which a magnetic tape is wound;   a rotary head mounted on said rotary drum and having a rotary transformer with a movable coil and a fixed coil;   a transformer having its secondary connected to said fixed coil of said rotary transformer;   a source of input signals to be recorded by a rotary head mounted on a rotary drum wound with a magnetic tape;   a first differential amplifier means having a first and a second transistor each having a base to which signals representative of said input signals are inputted, an emitter supplied with constant current signal, and a collector from which an output signal representative of an amplified output of said signals representative of said input signals are obtained, said first differential amplifier means being located at a location relatively remote from said rotary drum;   a second differential amplifier means having a third and a fourth transistor each having an emitter respectively connected to a collector of said first and said second transistors in said first differential amplifier means by wires, a base provided with a constant potential, and a collector from which outputs of said third and fourth transistors are provided to said rotary head, said second differential amplifier means being located at a location nearer to said rotary drum than said first differential amplifier means, said wires being extended between said emitters of said third and fourth transistors to said collectors of said first and second transistors, whereby an effect of distributed capacitance of said wires is reduced, wherein said second differential amplification means including an output transformer, a midpoint of a primary winding of Which is connected to a power source, wherein both ends of said primary winding of said output transformer are respectively connected to collectors of said third and fourth transistors, a secondary winding of said output transformer is connected fixed-side winding of a rotary transformer rotating with said rotary head, and said collector outputs of said second differential amplification means are applied to said rotary head through said output transformer and said rotary transformer.